Were there any UM segments that were filmed and then never used? Does anyone know?

To my knowledge, the only one was on their spinoff show "Final Appeal" where the episode featuring Thomas Drake was filmed but never aired. It would later be resurrected during the Farina reboot.

Were there any UM segments that were filmed and then never used? Does anyone know?

There is a segment about a missing woman filmed in the early 2000s that was never aired because her husband sent a letter to the producers and presumably threatened legal action.

https://charleyproject.org/case/sharon-eugenia-davis

It’s pretty obvious what happened to Sharon.